1. Field of the Invention
The present invention relates to a display apparatus and a method of driving a display apparatus. More particularly, the present invention relates to a liquid crystal display and a method of driving a liquid crystal display.
2. Description of the Related Art
Conventionally, an STN (Super-Twist-Nematic) type of a liquid crystal display panel has been used in a display apparatus of a portable electronic apparatus such as a portable telephone, a mobile terminal and a pager. On the contrary, even the portable electronic apparatus recently begins to employ an active matrix drive method represented by a TFT (Thin-Film-Transistor) method suitable for a display apparatus of a color dynamic picture.
The portable electronic apparatus requires that a consumptive power is especially reduced since a large restriction is put on a battery capacity. The portable electronic apparatus does not require that an indication is carried out on a whole surface of a liquid crystal display panel, for example, in a wait time. It is sufficient to carry out a minimum indication such as a reception level, a battery remaining amount, a date and hour and the like. Thus, it may be considered to reduce the consumptive power at a section which does not require a usual indication on the liquid crystal display panel.
Conventionally, in a passive matrix drive type of a portable electronic apparatus represented by the STN type, the technique for reducing the consumptive power at the section which does not require the usual indication on the liquid crystal display panel is disclosed in the following conventional techniques 1 to 5.
Japanese Laid Open Patent Application (JP-A-Showa, 63-243921) (Conventional Technique 1) discloses the following liquid crystal display. A signal electrode of a matrix liquid crystal panel composed of a scan electrode and a signal electrode is divided into two regions. This is designed as follows. That is, it is driven such that in a period of a selective scan within one region in the two regions, the other region has a voltage non-application period and a non-selective voltage application period at a predetermined cycle. Also, the same voltage as the signal voltage applied to the signal electrode of the selective scan region is applied to the signal electrode of the region on which the selective scan is not performed, in the non-selective voltage application period.
Japanese Laid Open Patent Application (JP-A-Heisei, 6-95621) (Conventional Technique 2) discloses the following liquid crystal display controller. The liquid crystal display controller for controlling a display apparatus of a liquid crystal panel has a driver for dividing a display region of the liquid crystal panel into a plurality of partial display regions, and making a partial display region selected by an external control signal at a drive state and making the other partial display regions at a non-drive state.
Japanese Laid Open Patent Application (JP-A-Heisei, 7-281632) (Conventional Technique 3) discloses the following liquid crystal display. This has a common electrode in using an entire region of a liquid crystal display panel targeted for a display apparatus, a common electrode in using a partial region of the liquid crystal display panel having an effective peak value smaller than a drive voltage to a segment electrode, and a power supply circuit for switching and outputting the drive voltage to the segment electrode through an operation of a switch. It drives by switching between the segment electrode and the common electrode corresponding to the partial region or the entire region of the liquid crystal display panel, in accordance with the drive voltage from the power supply circuit.
Japanese Laid Open Patent Application (JP-A-Heisei, 11-311980) (Conventional Technique 4) discloses the following liquid crystal display controller. A drive bias selection register and a drive duty selection register that can be rewritten from a micro processor are mounted within the liquid crystal display controller. When it is switched from an entire indication on the liquid crystal display panel to only some lines, setting values of the drive duty selection register and the drive bias selection register are changed to selectively carry out the indication on a part of the liquid crystal display panel at a low voltage drive and a low duty drive.
Japanese Laid Open Patent Application (JP-A-Heisei, 11-311981) (Conventional Technique 5) discloses the following method of driving a liquid crystal display. The method of driving a liquid crystal display has a liquid crystal display panel having a displayable region generated in accordance with a plurality of scanning lines and a plurality of signal lines crossing each other and has a function of making only a part of the displayable region at a display state and making the other regions at a non-display state. In this method, a period is established for controlling a display gradation of a non-display region to attain the non-display state.
WO 97/22036 (Japanese Patent Application No. (Heisei) 9-518751) (Conventional Technique 6) discloses a method of driving a display apparatus. The number of voltage levels of scanning lines at a time of a non-selection is only one. If an indication through a display element is not carried out, a voltage level of a data line corresponding to the display element is used as a voltage level at the time of the non-selection of the scanning line.
The above-mentioned conventional techniques relate to the passive matrix drive method. Since its driving method is different, it can not be applied in its original state to the active matrix driving method.
It is desirable to attain a low consumptive power manner optimal for the driving method of the active matrix drive type.
The present invention is accomplished in view of the above mentioned problems.
Therefore, an object of the present invention is to provide a display apparatus that can reduce a consumptive power.
Another object of the present invention is to provide a display apparatus of an active matrix drive type represented by a TFT method that can reduce a consumptive power.
Still another object of the present invention is to provide a liquid crystal display apparatus that does not suffer from a bad influence caused by an application of a direct current voltage and can reduce a consumptive power. Still another object of the present invention is to provide a display apparatus of an active matrix drive type represented by a TFT method that does not suffer from a bad influence caused by an application of a direct current voltage and can reduce a consumptive power.
In order to achieve an aspect of the present invention, a display apparatus, includes: a plurality of scanning lines to which a plurality of scanning signals are inputted, respectively; a plurality of signal lines to which a plurality of display signals are inputted, respectively; a plurality of capacitance sections respectively provided through a plurality of switching elements at a plurality of intersections of the plurality of scanning lines and the plurality of signal lines; and a display section including the plurality of capacitance sections, and wherein the display section is divided into first and second display regions by a virtual line parallel to at least one of the plurality of scanning lines, and wherein the plurality of scanning signals are inputted at first intervals to a first group of the scanning lines corresponding to the first display region of the plurality of scanning lines, and wherein the plurality of scanning signals are inputted at second intervals different from the first intervals to a second group of the scanning lines corresponding to the second display region of the plurality of scanning lines.
In this case, the first intervals are selected such that the plurality of capacitance sections of the first display region are driven at alternating currents, and wherein the second intervals are selected such that the plurality of capacitance sections of the second display region are driven at alternating currents.
Also in this case, when the plurality of scanning signals are inputted to the second group of the scanning lines, the plurality of display signals inputted to the plurality of capacitance sections of the second display region have amplitudes substantially identical with each other.
Further in this case, when the plurality of scanning signals are not inputted to the second group of the scanning lines based on a difference between the first and second intervals, a plurality of specific display signals having amplitudes substantially identical with the amplitudes of the plurality of display signals inputted to the plurality of capacitance sections of the second display region when the plurality of scanning signals are inputted to the second group of the scanning lines, are outputted to the plurality of signal lines at the same timings as when the plurality of scanning signals are inputted to the second group of the scanning lines.
In this case, the amplitudes of the plurality of specific display signals are substantially zero.
Also in this case, when the plurality of scanning signals are not inputted to the second group of the scanning lines based on a difference between the first and second intervals, potentials of the plurality of signal lines are dropped at the same timings as when the plurality of scanning signals are inputted to the second group of the scanning lines.
Further in this case, when the plurality of scanning signals are not inputted to the second group of the scanning lines based on a difference between the first and second intervals, the plurality of signal lines are in floating states at the same timings as when the plurality of scanning signals are inputted to the second group of the scanning lines.
In this case, when the plurality of scanning signals are not inputted to the second group of the scanning lines based on a difference between the first and second intervals, potentials of the second group of the scanning lines are dropped at the same timings as when the plurality of scanning signals are inputted to the second group of the scanning lines.
Also in this case, the display apparatus, further includes: a first shift resister supplying the plurality of scanning signals to the first group of the scanning lines by transferring a first input signal one by one; and a second shift resister supplying the plurality of scanning signals to the second group of the scanning lines by transferring a second input signal one by one.
Further in this case, the display apparatus, further includes: a shift resister supplying the plurality of scanning lines to the plurality of scanning signals by transferring an input signal one by one, and wherein the shift resister has a switch to stop transferring the input signal such that the plurality of scanning signals are supplied to the first group of the scanning lines and the plurality of scanning signals are not supplied to the second group of the scanning lines.
In this case, the input signal is transferred in a predetermined direction in the shift resister, and wherein a first input section inputting the input signal is provided in the most upstream in the predetermined direction of the first group of the scanning lines in the shift resister, and wherein a second input section inputting the input signal is provided in the most upstream in the predetermined direction of the second group of the scanning lines in the shift resister.
Also in this case, each of the first and second intervals corresponds to a multiple of a period of a frame when a single image is displayed in the display section, and wherein the display apparatus further comprises: a control section detecting the number of the frames to switch between an ON state and an OFF state of the switch based on the detected result.
In order to achieve another aspect of the present invention, a display apparatus, includes: a plurality of scanning lines to which a plurality of scanning signals are inputted, respectively; a plurality of signal lines to which a plurality of display signals are inputted, respectively; a plurality of capacitance sections respectively provided through a plurality of switching elements at a plurality of intersections of the plurality of scanning lines and the plurality of signal lines; and a display section including the plurality of capacitance sections, and wherein the display section is divided into first, second and third display regions by two virtual lines parallel to at least one of the plurality of scanning lines, and wherein the plurality of scanning signals are inputted at first intervals to a first group of the scanning lines corresponding to the first display region of the plurality of scanning lines, and wherein the plurality of scanning signals are inputted at second intervals to a second group of the scanning lines corresponding to the second display region of the plurality of scanning lines, and wherein the plurality of scanning signals are inputted at third intervals to a third group of the scanning lines corresponding to the third display region of the plurality of scanning lines, and wherein at least one of the first, second and third intervals is different from a remaining one in a case that the at least one is withdrawn from the first, second and third intervals.
In this case, the switching element is one of a TFT (Thin-Film-Transistor) type and an MIM (Metal-Insulator-Metal) type.
Also in this case, the display apparatus is provided on a single substrate.
In order to achieve still another aspect of the present invention, a portable electronic apparatus having a display apparatus which includes: a plurality of scanning lines to which a plurality of scanning signals are inputted, respectively; a plurality of signal lines to which a plurality of display signals are inputted, respectively; a plurality of capacitance sections respectively provided through a plurality of switching elements at a plurality of intersections of the plurality of scanning lines and the plurality of signal lines; and a display section including the plurality of capacitance sections, and wherein the display section is divided into first and second display regions by a virtual line parallel to at least one of the plurality of scanning lines, and wherein the plurality of scanning signals are inputted at first intervals to a first group of the scanning lines corresponding to the first display region of the plurality of scanning lines, and wherein the plurality of scanning signals are inputted at second intervals different from the first intervals to a second group of the scanning lines corresponding to the second display region of the plurality of scanning lines.
In order to achieve yet still another aspect of the present invention, a driving method of a display apparatus, includes: (a) providing a plurality of scanning lines to which a plurality of scanning signals are inputted, respectively; (b) providing a plurality of signal lines to which a plurality of display signals are inputted, respectively; (c) providing a plurality of capacitance sections respectively provided through a plurality of switching elements at a plurality of intersections of the plurality of scanning lines and the plurality of signal lines; (d) providing a display section including the plurality of capacitance sections; (e) dividing the display section into first and second display regions by a virtual line parallel to at least one of the plurality of scanning lines; (f) inputting the plurality of scanning signals at first intervals to a first group of the scanning lines corresponding to the first display region of the plurality of scanning lines; and (g) inputting the plurality of scanning signals at second intervals different from the first intervals to a second group of the scanning lines corresponding to the second display region of the plurality of scanning lines.
In this case, the first intervals are selected such that the plurality of capacitance sections of the first display region are driven at alternating currents, and wherein the second intervals are selected such that the plurality of capacitance sections of the second display region are driven at alternating currents.
Also in this case, when the plurality of scanning signals are inputted to the second group of the scanning lines, the plurality of display signals inputted to the plurality of capacitance sections of the second display region have amplitudes substantially identical with each other.
Further in this case, when the plurality of scanning signals are not inputted to the second group of the scanning lines based on a difference between the first and second intervals, a plurality of specific display signals having amplitudes substantially identical with the amplitudes of the plurality of display signals inputted to the plurality of capacitance sections of the second display region when the plurality of scanning signals are inputted to the second group of the scanning lines, are outputted to the plurality of signal lines at the same timings as when the plurality of scanning signals are inputted to the second group of the scanning lines.
The display apparatus of the present invention is based on the active matrix drive method, and has a plurality of regions having different refresh rates (a display rate, a write frequency and an gate-on period) on a single screen.
The active method is used to control the voltages applied to a scanning line of a second display region, a signal line, an opposite common electrode and a liquid crystal. Thus, it is possible to reduce a consumptive power and also possible to carry out a picture display (a middle between a static picture and a first display region) in which a picture change is smaller than that of a dynamic picture of the first display region (Since an accumulation voltage is dropped with an elapse of a time, a contrast of a picture may be dropped).